Regional comparison of impacts from seven Australian coal mine wastewater discharges on downstream river sediment chemistry, Sydney Basin, New south Wales Australia

This study investigates the accumulation of licensed and regulated coal mine wastewater pollutants from seven coal mines on each mines respective receiving waterways river sediments. Results from this study shows that the coal mine wastewater pollutants are accumulating within river sediments downstream of the coal mine wastewater inflows at varying levels often greater than the ANZECC guidelines for sediment and often above reference condition sediment concentrations. This is of great concern as these pollutants will likely continue to persist in the river sediment and eventually become legacy pollutants. Coal mine wastewater discharges in New South Wales are regulated by the New South Wales Environmental Protection Authority [NSW EPA] and environmental protection of receiving waterways is implemented through Environmental Protection Licenses. Environmental Protection Licenses set discharge limits for water quality and chemical concentrations within the coal mine waste waters. Though they do not take into account river sediment concentrations. It appears water column pollution regulation at these coal mines is in fact failing to protect the environment whilst still regulated and will continue into the future post mining, licensing and regulation. Water column regulation may well be impractical in protecting the environment as it appears that water column concentrations do not portray the overall environmental impact. It is recommended that the New South Wales Environmental Protection Authority investigate these findings and continue to improve water column pollutant limits as to alleviate the continued accumulation and magnification of the contaminants.